Paul’s main message from that passage is that it is more important to follow the ways of Jesus Christ than by the law and more important to go by the Spirit than the flesh. Paul was criticizing the Galatians because he felt that they didn’t learn anything from the death of Jesus.

The comparison between spirit/flesh and faith/law is referring to two different worlds. One world with no religion and the other one that does. Having law gives your flesh and having faith will give you spirit. Even though both flesh and law are important to life, it isn’t enough. In fact, the person can still be a sinner if he/she does not prioritizes the spirit and faith. This means that there a person can still drink, express rage and jealousy and show affinity to sorcery, but there really is no consequence for that because it is not against the law. These sinful acts are not the ways of God. Having law is not necessarily a bad thing, but the main problem is that law was created because people didn’t have faith in the first place. If everybody had faith, there wouldn’t even be law in the society in the first place. Choosing flesh is pretty much the loophole under the law. Choosing spirit means that the person has fully know the teachings of Jesus and the salvation. The person know about what God wants in an individual and the type of person to be in the Kingdom of God.

“By contrast, the fruit of the Spirit is love, joy, peace, patience, kindness, generosity, faithfulness, gentleness. There is no law against such things. And those who belong to Christ Jesus have crucified the flesh with its passion and desires. If we live by the Spirit, let us also be guided by the Spirit. let us not be conceited, competing against one another, envying one another.” (Galatians 5:22-26)

If one does not follow God, but the law, that person will still commit sinful manners that are not considered so under the law. Paul’s main message is to show that faith is the only true way to salvation.